Supermarket departments are typically designed and setup with remote refrigeration systems where remote refrigerated cases such as wall units and islands are installed with and controlled by central compressor banks/condensing units typically located in a back room or outside the building. In this type of installation, the condensate, which is water that condenses on the cooling coils then drips off, is drained into floor drains through permanently installed plumbing.
In some situations, it is desirable for the refrigerated cases to be of the self-contained design where the entire refrigeration system is contained within the refrigerator itself. Self-contained units may be used for adding additional refrigeration into store areas not originally designed in the store refrigeration system, for temporary or seasonal use, or for ease and low cost of department reconfiguring. Self-contained refrigerators may be permanently affixed to the floor or may be mobile thought the use of wheels or casters.
Removing condensate is of special concern where a floor drain and accompanying plumbing is not a viable option. In this situation, there are three options that are commonly used. The first is where condensate is eliminated by collecting and boiling it off in a pan having a heating element. The high electrical current draw of the heating element requires additional electrical service to the refrigerator, either by a significantly higher amperage circuit or the addition of another electrical circuit. The second option is to use the hot gas side of the refrigeration system and create a loop or coil that is immersed in a condensate collection pan. This option does not work as well as the heater pan since the condensate is often produced at a faster rate than the hot gas loop is able to remove under normal relative humidity conditions. In this case, excess condensate must be drained manually from the refrigerator. The third option requires periodic manual draining of the refrigerator.
Recently, the Department of Energy (DOE) started to implement their 2012 Energy Conservation Program, which regulates commercial refrigeration equipment. Its rules are mandatory for all manufacturers selling equipment in the United States. The program mandates maximum energy consumption dependent on the type model of the equipment. The traditional method of boiling away the condensate through the use of a heating element typically consumes more than one third of the total energy consumption requirement of prior generation refrigerators. Full-time electric heaters to boil off the condensate are no longer a viable method in terms of meeting energy consumption requirements. In response to this program, commercial manufacturers have started to address energy usage in their designs to meet the DOE 2012 program requirements.
What is now needed in the industry is a high efficiency refrigeration system that does not require periodic manual draining or emptying and does not require the additional electrical current load to support operation of a heating element thereby reducing the system's power consumption.